The only problem is that if the system is designed to mostly rely on people's integrity and honesty, it is very unfortunately a broken system from the very beginning. 

A good system is one that enforces honesty and integrity or at least encourages it. The systems based solely on trust and discretion of it's members do not survive much in our society or in our species for that matter, unfortunately.

Pareto principle works here too actually (20% / 80%)

It is very good that you brought up this subject. Maybe someone would listen to you. But i saw it right away, a system where your votes and power can be bought, sold, rented (delegated) and so on is a corrupt system. As they say if "you build it, they will come". If the system allows for abuse there will be always those who will exploit it to the fullest. So it is the system design that should be thought through to the core to close those loopholes.

The moral issue still remains, but unfortunately on a large scale it is more academic until the system is fundamentally fixed.